Insulator



MaYZ, 1944- v A. c. STEPHENS 2,347,975

INSULATOR Filed sept. 3,. 1941 Patented May 2, 1944 INSULATOR Allen C. Stephens, Washington, D. C., assignor to Utilities Service Company,

Inc., Allentown, Pa.,

a corporation of Pennsylvania Application September 3, 1941, Serial No. 409,405

4 Claims.

. This invention relates to insulators and more particularly to a supporting insulator for power and other cables extending into manholes.

Underground power and other cables extend through conduits which open at spaced intervals into manholes to provide access to the cables, and the portions of the cables in the manholes are supported on porcelain or similar insulators, The cables are relatively close together where they extend into a manhole and are spread out in the manhole to approximately follow the walls thereof and thus provide substantial working space centrally of the manhole. Obviously, the cables, as they enter the manhole, must be curved outwardly toward the side walls of the manhole and where the insulators support the curved portions of the cables, the latter do not lie directly within the cable-receiving grooves in the tops of the insulators but rather extend angularly thereacross.

It is desirable that the cable extend directly through and in alignment with the cable receiving grooves, and efforts have been made to provide insulators and supports therefor so constructed with relation to each other as to permit each insulator to swing in a horizontal plane to accommodate itself to the direction at which a cable extends at the point where it engages the insulator. These efforts have not been wholly successful for the reason that the insulator either is not so constructed as to permit sufiicient swinging movement or, if it does swing to a sufcient extent, is so structurally weakened as to be readily broken.

An important object of the present invention is to provide an insulator for supporting power and other cables which is so constructed as to permit it to swing to a suflicient extent to properly support a cable in the cable-receiving groove of the insulator at a point where the cable extends at a relatively sharp angle with respect to the normal direction of the cable-receiving groove.

A further object is to provide a device of this character wherein the structural strength of the insulator is not materially sacrificed, thus rendering the insulator wholly practicable for supporting the relatively heavy load imposed upon it by the cable.

A further object is to provide an insulator and a mounting therefor so constructed and arranged with respect to each other that when the insulator is turned in a horizontal plane to its limit of movement, the insulator provides a number of different points of contact with its supporting mounting so as to distribute strains on the insulator and thus minimize the chance of its breaking.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the drawing I have shown one embodiment of the invention. In this showing:

Figure 1 is a horizontal sectional view through a portion of a manhole and the conduits leading thereinto from one side thereof, showing the invention in operation,

Figure 2 is a bottom plan View of the insulator,

Figure 3 is a top plan View of the insulator in position on a supporting structure,

Figure 4 is a vertical sectional view through the insulator taken on line 4-4 of Figure 3, and,

Figure 5 is an underside perspective view of the insulator.l

Referring to Figure 1 the numeral I0 designates a conventional manhole into which power or other cables I I extend from a suitable conduit structure I2 of conventional type. The cables are bent outwardly in the manhole to provide a central space of substantial size in the manhole in accordance with conventional practice.

The present invention contemplates the provision of means for supporting the cables in the manhole and particularly at points where the cables are arranged at an acute angle to the direction at which they extend through the conduits. In the present instance the cables are shown as being supported on insulators each of which is indicated by the numeral I3, and will be referred to in detail later, and these insulators are arranged on a support indicated as a whole by the numeral I4. It will become apparent that the general type of support I4 is of no importance in connection with the invention so long as it possesses the mechanical features to be reierred to, and bracket arms mounted on the side walls of the manhole may be employed as the support, if desired. f

The support I4 in the present instance is preferably made up of a plurality of horizontal vertically spaced supporting units I5 each of which may be of inverted channel cross-section and provided centrally of its width with an elongated longitudinal slot I6. The supports i5 are connected at their ends to brackets I'I secured in turn to verticall bars I8 mounted against the side walls of the manhole. Vertical bars I9 are arranged at spaced points along the units I 5 and are connected to each unit by a bracket 20 having a bolt 2I the shank of which extends through the associated slot I6. This supporting structure forms no part per se of the present invention except in the combination to be referred to later.

Each linsulator I3 is preferably formed integrally of porcelain or any other suitable material and is provided in its upper' face with a transverse groove 22 forming a saddle to receive one of the cables II. At each side, the insulator is provided with a depending flange 23 each having inner faces 24 diverging from a point 25 intermediate the length of the insulator to a relatively thin edge 26 substantially intersecting the outer face of the corresponding flange 23,

Within the anges 23 the insulator is provided with a flat bottom face 21 from the center of which depends an integral lug 28 arranged centrally of the length and width of the insulator. The lug 2S is diamond shaped, being provided toward its ends with converging pairs of faces meeting substantially in points 3U. It will be apparent from an inspection of Figures 2 and 3 that each face 29 is parallel to and spaced from the plane of the race 24 at the corresponding side of the insulator and toward the opposite end thereof. The maximum width of the lug 28 is slightly less than the width of the slot I6 to per mit it to be received therein. The minimum width between the flanges 23, that is, between the edges 25, is slightly greater than the over- 5 all width of each supporting unit I5 to permit it to straddle one of such units.

The operation of the device is as follows:

One of the supports I4 is placed adjacent each end of the manhole or, if desired, any other types of racks may be employed, it merely being essential that each supporting unit be arranged substantially horizontally with a longitudinal slot extending therethrough parallel to the edges and equidistantly spaced therefrom if the lug 28 is arranged centrally of the width of the insulator. For each conduit opening through which a cable extends one of the insulators i3 is arranged over one of the supporting units l5 in a position to support the cable. position with the flanges 23 straddling the supporting unit I5 with the lug 2B arranged in the slot I6.

Each cable is therefore provided with its own individual insulator I3 to support it as shown in 'i Figure 1. As stated, the cables passing into the manhole fro-m the conduit are curved outwardly toward the sides of the conduit to provide a central space in the manhole of .substantial size to permit workmen to work therein. Where a cable i.

crosses one of the supporting units I5, therefore, the cable will be at an acute angle to the supporting unit. The provision of the angular faces 24 and 29 of the flanges and lug 28 respectively permits each insulator to turn in a horizontal plane to accommodate itself to the position of the cable thus permitting the latter to lie within and in alignment with the Saddle groove 23 in most cases. In actual practice it has been found that the wholly practicable design of the -ifi insulator permits it to turn at an angle of 30 degrees with respect to the direction of the conduits, and this angularity is sufficient to correspond in most instances with the angularity of a cable which crosses the supporting unit. some the angularity of the cable where it crosses the supporting unit will be as great as 45 degrees but it is unnecessary to provide for the turning of the insulator to such an angle. It will be apparent that if the insulator is turned The insulator is placed in L 30 degrees and the cable crosses it at an angle of 45 degrees, the cable will still rest sufiiciently within the groove 22 to prevent its displacement.

The extension of the angular faces 24 to the intersecting lines 25 centrally of the length of the insulator permits the latter to turn to a substantial angle while still necessitating a distance between the inersecting lines 25 only slightly greater than the width of its supporting unit I5. The same thing is true of the extension of the angular faces 2S to lines centrally of the length of the lug 2S. The angularity of the faces 29 corresponds to that of the faces 24 and accordingly these faces all cooperate to permit turning movement of the insulator to the same extent in a horizontal plane.

The present construction permits the maintenance of the insulator at a minimum width corresponding to the width of a conventional insulator, and it will be apparent that the extension of the angular faces 24 to the intersecting lines 2S renders the an'ges 24 relatively narrow at their ends. However, this does not seriously weaken the insulator since the provision of the structure of the lug 28 referred to is such that when outer end of either face 24 contacts with the side of the supporting unit, the outer end the diagonally opposite face 24 will contact with the opposite side of the supporting unit while at the same time end portions of the lug 28 adjacent the lines 3|] will contact with opposite sides of the slot IB. Whenever the insulator is turned to its limit of movement, therefore, it has four vertical points of contact with the supporting unit I5 to limit the turning movemen of the insulator` and this arrangement distributes strains to which the insulator may be subjected, thus preventing injury to the insulator such as the cracking off of the ends 26 thereof.

t is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

i. A cable-supporting insulator having an integral body provided with a cable-receiving groove extending across its upper face and hava bottom face adapted to rest on one face of a support, said body being provided with depending flanges adapted to be arranged on opposite sides of said support, said anges having inner faces diverging throughout their lengths from a point intermediate the length of said body, said body on the bottom face thereof being provided with a depending lug for reception in a slot formed in the support, said lug being of a size and shape relative to said slotl whereby said insulatoris movable relative to said support in a plane parallel to the face of the support on which said insulator rests.

A cable-supporting insulator having an integral body provided with a cable-receiving groove extending across its upper face and having a bottom face adapted to rest on a support. said body being provided with depending iianges adapted to be arranged on opposite sides of said support, said anges having inner faces diverging throughout their lengths from a point intermediate the length of said body, said body centrally of the width of the bottom face thereof being provided with a depending lug for reception in a slot formed in the support having substantially parallel longitudinal edges, said lug being approximately diamond shaped in horizontal section with each side face spaced from and parallel to the plane of the inner face of the flange at the same side of the insulator and toward the opposite end thereof.

3. In combination with a horizontal support having parallel longitudinal edges and a longitudinal slot intermediate the Width of the support and parallel to said edges, an insulator adapted to rest on one face of the support and having depending side flanges adapted to be arranged outwardly of the edges of the support and provided with inner faces diverging throughout their lengths from points intermediate the length of the insulator, said insulator being further provided with a depending lug engageable in the slot in the support, said lug being of a size and shape relative to said slot whereby said insulator is movable relative to said support in a plane parallel to the face of the support on which said insulator rests.

4. In combination with a horizontal support having parallel longitudinal edges and a longitudinal slot intermediate the width of the support and parallel to said edges, an insulator having depending side flanges adapted to be arranged outwardly of the edges of the support and provided with inner faces diverging throughout their lengths from points intermediate the length of the insulator, said insulator being further pro- 10 vided with a depending lug engageable in the slot in the support, said lug being diamond shaped in horizontalvcross-section with each side face parallel to and spaced from the plane of one inner face of the ange at the same side of the in- 15 sulator and toward the opposite end thereof whereby horizontal turning movement of the insulator to its limit of movement will cause opposite sides of the support to contact with opposite ends of the respective flanges and will 20 cause opposite sides of said slot to contact with opposite end portions of said lug.

ALLEN C. STEPHENS. 

